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Finding the Fourth Proportional to 141.42, 211.78 and 87.15

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Solution

The fourth proportional to 141.42, 211.78 and 87.15 is: 130.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    141.42 : 211.78 = 87.15 : x
  2. Step 2: Convert to fraction form
    141.42/211.78 = 87.15/x
  3. Step 3: Cross multiply
    141.42x = 211.78 × 87.15
  4. Step 4: Simplify right side
    141.42x = 18,456.63
  5. Step 5: Solve for x
    x = 18,456.63/141.42
  6. Step 6: Final answer
    x = 130.51

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.